Dermatographia is a condition also known as skin writing. When people who have dermatographia lightly scratch their skin, the scratches redden into a raised wheal similar to hives. These marks usually disappear within 30 minutes.

The cause of dermatographia is unknown, but it can be triggered in some people by infections, emotional upset or medications such as penicillin.

Most people who have dermatographia don't seek treatment. If your signs and symptoms are especially bothersome, your doctor may recommend allergy medications such as cetirizine (Zyrtec) or diphenhydramine (Benadryl).

Signs and symptoms of dermatographia may include:

Raised red lines

Swelling

Inflammation

Hive-like welts

Itching

The signs and symptoms may occur within a few minutes of your skin being rubbed or scratched and usually disappear within 30 minutes. Rarely, dermatographia develops more slowly and lasts several hours to several days.

The condition itself can last for months or years.

When to see a doctor

See your doctor if your signs and symptoms are particularly bothersome.

The exact cause of dermatographia isn't clear. It may be caused by an allergic response, yet no specific allergen has been identified.

Simple things can trigger symptoms of dermatographia. For example, rubbing from your clothes or bedsheets may irritate your skin. Sometimes, dermatographia is preceded by an infection, emotional upset or medications, such as penicillin.

Dermatographia can occur at any age, but it tends to be more common in teenagers and young adults. If you have other skin conditions, such as dry skin or dermatitis, you may be more susceptible to dermatographia. Any skin condition that causes a frequent urge to scratch may increase your risk.

You're likely to start by seeing your primary care doctor. However, in some cases when you call to set up an appointment, you may be referred immediately to a doctor who specializes in skin conditions (dermatologist) or one who specializes in allergies (allergist).

Here's some information to help you prepare for your appointment.

What you can do

At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as not take antihistamines for several days beforehand.

You may also want to:

Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.

Write down key personal information, including any major stresses or recent life changes.

Make a list of all medications, vitamins or supplements you're taking.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

When did you begin experiencing symptoms?

Were your symptoms preceded by an illness or a new medication?

Have your symptoms been continuous or occasional?

How severe are your symptoms?

Do your symptoms cause you to restrict your activities or interfere with your lifestyle?

Do you have allergies? To what?

Do you have dry skin or any other skin conditions?

Does anything improve your symptoms?

Does anything make your symptoms worse?

Your doctor can diagnose dermatographia with a simple test. He or she will draw a tongue depressor across the skin of your arm or back to see if a red, swollen line or a welt (wheal) appears within a few minutes.

Symptoms of dermatographia usually go away on their own, and treatment for dermatographia generally isn't necessary. However, if the condition is severe or bothersome, your doctor may recommend antihistamine medications such as diphenhydramine (Benadryl), fexofenadine (Allegra) or cetirizine (Zyrtec).

To reduce discomfort and prevent the symptoms of dermatographia, try these tips:

Avoid irritating your skin. Refrain from using harsh soaps on your skin. Don't wear clothing made of itchy material, such as wool. Hot showers or baths may worsen the symptoms.

Don't scratch your skin. If you have dermatographia or other skin conditions that may cause frequent itching, try to avoid scratching your skin. Scratching will aggravate the condition.

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